Although the individual domains of MxiC and YopN–TyeA adopt similar folds (rmsd over Cα atoms of the first and second domains of MxiC with the equivalent regions of YopN of 3.9 Å and 3.2 Å, respectively, and the third domain of MxiC with TyeA of 0.8 Å), the arrangement of these domains results in a different overall shape for these molecules (Fig. 3b). This structural rearrangement differs from the “wobble” seen between different MxiC molecules and is particularly noticeable in one orientation (Fig. 3b, top panel). This view highlights the straight conformation adopted by MxiC and the relative curvature of the YopN–TyeA complex. The different position and orientation of the first domain of MxiC may be due, in part, to the missing N-terminal portion, as the YopN–TyeA structure possesses an additional helix at its N terminus.